How Long Mushrooms Last And How To Increase Their Shelf Life

​How Long Do Mushrooms Last after purchase?

When I go grocery shopping, I like to plan out many meals in advance. When you do this, you can stock up on many different items. I understand that the self-life of many of these items can be a concern when buying in advance.

Mushrooms are one healthy item that often find their way into my shopping cart. They are a versatile and delicious food that can bring new flavors and textures to your cooking.

I know it can be frustrating when the ingredients go bad before you have had a chance to use them. When planning out meals you have to be aware how long the mushroom will last in your refrigerator, so I am going to tell you how long you can expect mushrooms to be fresh before turning bad.

​How long do mushrooms last? How long are mushrooms good for?

If you wondered how long are mushrooms good for, you should know that on average a mushroom that you buy from the store will last about two weeks if regenerated. Depending on how long they have been on the store shelf this may be even sooner, though your chances of mushrooms going bad increases significantly around the two-week mark. This two-week window assumes you will be storing the mushrooms in a refrigerator.

There are some factors that can change this two-week window. I like whole mushrooms, and whole mushrooms will likely last for the entire two weeks, but a sliced mushroom has been exposed and the timeline may be cut down by about half. The reasoning behind this is that whole mushrooms have a less exposed surface area. By slicing up the mushroom, you are increasing the area exposed to the elements that make them go bad.

​How do I know if my mushrooms have gone bad?

Well, your first test should be a sight test. You can gain a lot of information by just taking a look at the mushroom. Bad mushrooms grow dark spots. These dark spots are the first sign that a mushroom is starting to go south, and it will not be long until they are unsafe.

Keep a close eye on the shade of your mushrooms and take note when they start to darken. If I notice my mushroom star to develop these spots, I use them right away. They may still be safe if you catch the color change quickly enough.

Your other senses can also help out to suss out if your fungus is bogus. If a sight test is inconclusive, give your mushrooms a sniff test. If they smell funny or strange, then they may have just gone bad. I have found there is a large difference between the small of fresh mushrooms and ones that have gone bad. Fresh mushrooms should not give off much of an odor, and the smell given off by a fresh and safe mushroom will be subtle and light. If I smell a strong odor as I open a container, I throw them out.

If all else fails, give them a poke. Mushrooms that have gone bad will become slimy. A slimy mushroom is a positive indicator that a mushroom is dangerous to eat. Any slimy mushrooms should be tossed away immediately.

​Mushroom Shelf Life

​Sometimes a mushroom will not get slimy, but will dry out and wrinkle instead. Wrinkles are visible indicators of mushrooms shelf life deterioration. I know there are some techniques to dry out mushrooms, but be careful as to when they start to wrinkle on their own, at which point they are no longer safe to consume.

​If any of these tests provide results, your mushrooms may be bad and you may be safer steering clear of that batch. In the end, it is up to your best judgment. These tests can help give you an idea of when things have turned sour, but since bad mushrooms can make you sick, err on the side of caution.

​How do I lengthen the life of my mushrooms?

To prevent premature spoiling of your mushrooms, you will have to store them properly. There are ways to store them that will even elongate their shelf life.

First and foremost, I suggest you let your fresh mushrooms breathe. I use a paper bag, which is a wonderful container for fungi as it will let in the right amount of air. If you bought the mushrooms in a shrink wrapped container, you usually can just leave them in your refrigerator in that packaging until you are ready to use them.

If you see your mushrooms starting to head in a bad direction, you can brown them up in a pan with some oil which will extend their life by a few days. After browning put them in a suitable container and place them back in the refrigerator. I like to do this anyway, as it saves me the mushroom cooking step when I get around to putting a dish together.

Another way to extend their shelf life is by freezing. This can be a bit more tricky than freezing other ingredients, though, as mushrooms retain much more water than other foods that you may freeze. To properly freeze raw mushrooms you will want to place them on parchment paper and in an airtight bag. Press as much air out of the bag as you can before sealing.

It is risky and difficult to properly freeze raw mushrooms, so I recommend cooking them before freezing. If you blanch, saute, or steam the mushrooms, place them into an airtight container and then freeze them to significantly extend their life. Once frozen, mushrooms should last up to a month.

​Better safe than sorry . . .

Mushrooms can typically last two weeks refrigerated. Sliced mushrooms will go bad faster than whole mushrooms.

To tell if your mushrooms have gone bad, look out for the warning signs:

​Dark spots

​Strong odor

​Slimy

​Wrinkles

At first sight of dark spots, the mushrooms are starting to turn. They may still be saveable if cooked or used right away. If they have gotten to a point where they are slimy or smelly, they are dangerous to consume and should be thrown away.

If you want to increase the shelf life of your mushrooms, there are a few things you can do.